Survival After Implantable Cardioverter-Defibrillator Implantation in the Elderly

Abstract

I mplantable cardioverter-defibrillators (ICDs) used in appropriately selected patients at high risk of sudden cardiac death are associated with reduction in arrhythmic death. 1 Recommendations for ICDs are based on large randomized, controlled trials, which often enroll highly selected patients who are often young with few comorbidities. In contrast, the average patient with heart failure and severe left ventricular systolic dysfunction is aged >65 years with multiple comorbidities. With the aging population, the number of elderly patients being considered for ICD implantation is increasing, and an estimated 28% of those deemed potentially eligible by conventional criteria are octogenarians.2 However, with advancing age and comorbidity burden, the relative contribution of nonarrhythmic causes of death may increase, 3,4 potentially attenuating the benefits of ICD therapy. Current guidelines do not specifically address the appropriateness or prognosis of ICD implantation with advanced age. 1,5,6 Clinical Perspective on p 2392Randomized trials can underrepresent elderly patients, while population-based registries may illuminate the impact and outcomes of ICDs implanted in this group. The Ontario ICD Database is a large, population-based, prospective registry of ICD recipients referred for primary or secondary prevention defibrillator implantation. Using this registry, we examined all-cause mortality, appropriate and inappropriate defibrillator shocks, hospitalization, and early complications in elderly ICD Background-The benefit of implantable cardioverter-defibrillators (ICDs) among elderly patients is controversial and may be attenuated by nonarrhythmic death. We examined the impact of age on device-delivered therapies and outcomes after primary or secondary prevention ICD. Methods and Results-In a prospective, inclusive registry of 5399 ICD recipients in Ontario, Canada (February 2007 to September 2010), device-delivered therapies and complications were determined at routine clinic visits. Among primary prevention ICD recipients aged 18 to 49 (n=317), 50 to 59 (n=769), 60 to 69 (n=1336), 70 to 79 (n=1242), and ≥80 (n=275) years, mortality increased with age, as follows: 2.1, 3.0, 5.4, 6.9, and 10.2 deaths per 100 person-years, respectively (P<0.001). Secondary prevention ICD recipients aged 18 to 49 (n=114), 50 to 59 (n=244), 60 to 69 (n=481), 70 to 79 (n=462), and ≥80 (n=159) years also exhibited increasing mortality, as follows: 2.2, 3.8, 6.1, 8.7, and 15.5 deaths per 100 person-years, respectively (P<0.001). However, rates of appropriate shock were similar across age groups: from 6.7 (18-49 years) to 4.2 (≥80 years) per 100 person-years after primary prevention ICDs (P=0.139) and from 11.4 (18-49 years) to 11.9 (≥80 years) per 100 person-years after secondary prevention ICDs (P=0.993). Covariate-adjusted competing risk analysis demonstrated higher risk of death (P trend <0.001 for both primary and secondary prevention) but no significant decline in appropriate shocks with older age after primary (P=0.130) ...

Response to Letter Regarding Article, “Survival After Implantable Cardioverter-Defibrillator Implantation in the Elderly”

“…1 We agree that rates of device therapies with conventional programming may overestimate the potential benefit of ICD implantation. Barra and Agarwal suggest that device programming approaches that were used in the Primary Prevention Parameters Evaluation (PREPARE), 2 Multicenter Automatic Defibrillator Implantation Trial -Reduce Inappropriate Therapy (MADIT-RIT), 3 and Avoid Delivering Therapies for Non-sustained Arrhythmias in ICD Patients III (ADVANCE III) 4 trials would lead to rates of appropriate shock and therapy that better reflect the occurrence of ventricular tachyarrhythmia episodes that would more likely have been associated with an arrhythmic death.…”

Outcome of Apparently Unexplained Cardiac Arrest

“…[38][39][40] This study supports the HRS guidelines for implantation of ICD in those with an unexplained cardiac arrest. 36 Although this study was not powered to provide a robust estimate of annual shock rate, the numbers were less than populations previously reported in primary prevention populations 41,42 but comparable with heart failure populations with results from Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) reporting an annual shock rate of 7.5%. 43 …”

Clinical Outcomes of Single‐ versus Dual‐Chamber Implantable Cardioverter Defibrillators: Lessons from the Israeli ICD Registry

“…In keeping with well-documented data, mortality rates were higher in patients with advanced age, and low left ventricular ejection fraction, regardless of device type, after adjustment for multiple variables. 7,8 Physicians continue to implant more dual-chamber devices despite the lack of evidence for their superiority in the setting of primary prevention without an indication for pacing. The majority of patients in the present study were implanted with a dual-chamber ICD (63%), even in the absence of any clear indication for pacing.…”